Daewoo Electronics Corporation

Daewoo Electronics Co., Ltd.

Byung-Bok Kang

Jae-Woo Roh

The present invention provides a method and apparatus for preprocessing a page image reproduced from a storage medium in a holographic system. The present invention calculates pixel sums for each lines in the page image to select a maximum sum, calculates a modified maximum sum using the modified maximum sum and its neighboring sums, determines a compensation location for distorted pixels using the modified maximum sum and performs over-sampling a data image with reference to the compensation location of magnified pixels, to thereby compensate the data image with high precision in sub-pixels.

Method and apparatus for compensating data image reproduced from holographic system

In an apparatus for processing holographic data reproduced from a holographic medium, a data arranging unit arranges input data in a form of M1&#xd7;M2 data pixels on a page basis to thereby generate arranged data. Then, a holographic data detector outputs a page image including a detected data image, each data pixel of the arranged data corresponding to P1&#xd7;P2 image pixels of the detected data image. Thereafter, a resized pixel detector finds a resized vertical length V and a resized horizontal length H of the detected data image. Finally, a sampling unit extracts image pixels at different intervals depending on whether the horizontal length and/or the vertical length of the detected data image is increased or decreased.

Apparatus and method for processing holographic data reproduced from a holographic medium

In an apparatus for detecting holographic data reproduced from a holographic medium, the holographic medium has an interference pattern and the holographic data is reproduced when a first portion of a reference beam is diffracted by the interference pattern within the holographic medium. A transmission beam detector detects a light intensity of a transmission beam which is a second portion of the reference beam, wherein the transmission beam is not diffracted to reproduce the holographic data and passes through the holographic medium. Then, a CCD (charge coupled device) controller generates a driving signal in accordance with the detected light intensity. Thereafter, a CCD detects the holographic data in response to the driving signal.

Apparatus and method for detecting holographic data reproduced from a holographic media

In a holographic digital data storage system, holographic page data has at least two concentric patterns with the optical information arranged within an outermost pattern of at least two concentric patterns. Since at least two concentric patterns in the holographic page data are deformed into at least two elliptic patterns in the diffracted beam caused by irradiation of the reference beam, at least two elliptic patterns are extracted from the diffracted beam and then at least two elliptic patterns are estimated to generate at least two estimated concentric patterns. A compensated vector between said at least two elliptic patterns and said at least two estimated concentric patterns is used to reconstruct the optical information from the diffracted beam.

Method and apparatus for recording/reproducing optical information

A method for correcting an error in N:N&plus;1 channel codes categorizes 2 codeword (N&plus;1)-tuples into M subsets of codeword (N&plus;1)-tuples, wherein each subset G has N codeword (N&plus;1)-tuples and the total number of codeword (N&plus;1)-tuples in the M subsets is and wherein each subset G has a predetermined number K of lower bits and a predetermined number (N&plus;1&minus;K ) of higher bits and the number of lower bits in every codeword (N&plus;1)-tuple in any subset is not equivalent to that of lower bits in every codeword (N&plus;1)-tuple in any other subset. The 2 message N-tuples are mapped with said 2 codeword (N&plus;1)-tuples in the M subsets, respectively, in one-to-one correspondence to generate a lookup table.

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Seoul, South Korea

Byung-Bok Kang